Guru
Joined: 05/10/2019
Location: United KingdomPosts: 9128
| Posted: 07:56am 30 Nov 2025 |
At it's fundamental frequency an open ended tube has an antinode at each end and in the centre, where it has it's greatest movement. There will be two node points that are at 0.224xL (where L is the length of the tube) from each end. Any supports, whether for hanging or for horizontal tubes or bars should be at these points only. It doesn't matter whether or not there are unused holes at these points as the object isn't moving.
Another thing about hitting tubes is that they don't produce harmonics but they do produce overtones. These are not always related to the fundamental and can sound rather nasty (bells do this too). One of the best ways to reduce these is to use a soft striker rather than a hard one. The other way is to use some sort of mechanical damping at positions along the tube where they are produced, but that gets a bit complicated as you don't want to damp the fundamental.
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Edited 2025-11-30 18:09 by Mixtel90